Well, IOA and US are two different places. If your kids like thrill rides, then you'd want to go to IOA. But US doesn't have the same Disney hospitality. If if was out of US or MGM, definetly MGM.
When we went to US, the people who worked there didn't tell you where to go; it was like you were expected to know where you're going even if you don't. On Back to the Future (which were great movies

) The US employee just told us to walk down the hall to get to the briefing room, but there were like 3 open doors, and we didn't know where to go! Then when we were getting into the car, the people were still getting out of it, and we didn't know when to get in. I don't know how I managed this, but I ended up going through the window or something to get into the car. When I was already in, that's when the doors went up

(I always seem to make things harder than they really are

)
Then, on the Hanna- Barbera ride, You just walk in and get on a line. The doors into the theatre were open, but I didn't know if I was supposed to go or not, and then the person working there is like Go!! And I was just like, what is
your problem.
Most of the employees (I don't want to call the 'cast members') didn't say hi, how are you, like in WDW, but one guy was empting the trash and said hi to us.
So, if it's between MGM and US, go with MGM. If it's between IOA and MGM and your kids like thrill rides, go with IOA. If they don't go to MGM.
I like thrill rides, but no one in my family would go on them with me.
Hope that helped
